如果之前有过中国国籍，没有主动注销
中国zf对你有管辖权，在中国zf觉得有必要时，比如你犯事了，而且英国政府也提示这一点了
Dual nationality
China doesn’t recognise dual nationality. If you enter China on a Chinese passport or identity card, the British Embassy may not be able to offer you help. If you were born in China to a Chinese national parent you will be considered by the Chinese authorities to have Chinese nationality, and may be treated as a Chinese citizen, even if you used a British passport to enter China. If you have formally renounced Chinese citizenship, you should carry clear evidence that you have done so.